Methods of manufacture of top port surface mount MEMS microphones

ABSTRACT

Methods for manufacturing multiple top port, surface mount microphones, each containing a micro-electro-mechanical system (MEMS) microphone die, are disclosed. Each surface mount microphone features a substrate with metal pads for surface mounting the package to a device&#39;s printed circuit board and for making electrical connections between the microphone package and the device&#39;s circuit board. The surface mount microphones are manufactured from a panel of unsingulated substrates, and each MEMS microphone die is substrate-mounted. Individual covers, each with an acoustic port, are joined to the panel of unsingulated substrates, and each individual substrate and cover pair cooperates to form an acoustic chamber for its respective MEMS microphone die, which is acoustically coupled to the acoustic port in the cover. The completed panel is singulated to form individual MEMS microphones.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/838,319, filed Mar. 15, 2013, which is a continuation of U.S. patentapplication Ser. No. 13/732,120 (now U.S. Pat. No. 8,624,385), filedDec. 31, 2012, which is a continuation of U.S. patent application Ser.No. 13/286,558 (now U.S. Pat. No. 8,358,004), filed Nov. 1, 2011, whichis a continuation of U.S. patent application Ser. No. 13/111,537 (nowU.S. Pat. No. 8,121,331), filed May 19, 2011, which is a continuation ofU.S. patent application Ser. No. 11/741,881 (now U.S. Pat. No.8,018,049), filed Apr. 30, 2007, which is a divisional of U.S. patentapplication Ser. No. 10/921,747 (now U.S. Pat. No. 7,434,305), filedAug. 19, 2004, which is a continuation-in-part of U.S. patentapplication Ser. No. 09/886,854 (now U.S. Pat. No. 7,166,910), filedJun. 21, 2001, which claims the benefit of U.S. Provisional PatentApplication No. 60/253,543, filed Nov. 28, 2000. U.S. patent applicationSer. No. 13/668,035, filed Nov. 2, 2012, and U.S. patent applicationSer. No. 13/668,103, filed Nov. 2, 2012, are also continuations of U.S.patent application Ser. No. 13/286,558. These applications are herebyincorporated by reference herein in their entireties for all purposes.

TECHNICAL FIELD

This patent relates generally to a housing for a transducer. Moreparticularly, this patent relates to a silicon condenser microphoneincluding a housing for shielding a transducer.

BACKGROUND OF THE INVENTION

There have been a number of disclosures related to building microphoneelements on the surface of a silicon die. Certain of these disclosureshave come in connection with the hearing aid field for the purpose ofreducing the size of the hearing aid unit. While these disclosures havereduced the size of the hearing aid, they have not disclosed how toprotect the transducer from outside interferences. For instance,transducers of this type are fragile and susceptible to physical damage.Furthermore, they must be protected from light and electromagneticinterferences. Moreover, they require an acoustic pressure reference tofunction properly. For these reasons, the silicon die must be shielded.

Some shielding practices have been used to house these devices. Forinstance, insulated metal cans or discs have been provided.Additionally, DIPs and small outline integrated circuit (SOIC) packageshave been utilized. However, the drawbacks associated with manufacturingthese housings, such as lead time, cost, and tooling, make these optionsundesirable.

SUMMARY OF THE INVENTION

The present invention is directed to a silicon condenser microphonepackage that allows acoustic energy to contact a transducer disposedwithin a housing. The housing provides the necessary pressure referencewhile at the same time protects the transducer from light,electromagnetic interference, and physical damage. In accordance with anembodiment of the invention a silicon condenser microphone includes atransducer and a substrate and a cover forming the housing. Thesubstrate may have an upper surface with a recess formed thereinallowing the transducer to be attached to the upper surface and tooverlap at least a portion of the recess thus forming a back volume. Thecover is placed over the transducer and includes an aperture adapted forallowing sound waves to reach the transducer.

Other features and advantages of the invention will be apparent from thefollowing specification taken in conjunction with the followingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a first embodiment of a siliconcondenser microphone of the present invention;

FIG. 2 is a cross-sectional view of a second embodiment of a siliconcondenser microphone of the present invention;

FIG. 3 is a cross-sectional view of a third embodiment of a siliconcondenser microphone of the present invention;

FIG. 4 is a cross-sectional view of the third embodiment of the presentinvention affixed to an end user circuit board;

FIG. 5 is a cross-sectional view of the third embodiment of the presentinvention affixed to an end user circuit board in an alternate fashion;

FIG. 6 is a plan view of a substrate to which a silicon condensermicrophone is fixed;

FIG. 7 is a longitudinal cross-sectional view of a microphone package ofthe present invention;

FIG. 8 is a lateral cross-sectional view of a microphone package of thepresent invention;

FIG. 9 is a longitudinal cross-sectional view of a microphone package ofthe present invention;

FIG. 10 is a lateral cross-sectional view of a microphone package of thepresent invention;

FIG. 11 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 12 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 13 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 14 a is a cross-sectional view of a laminated bottom portion of ahousing for a microphone package of the present invention;

FIG. 14 b is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 14 c is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 14 d is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 15 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 16 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 17 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 18 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 19 is a plan view of a side portion for a microphone package of thepresent invention;

FIG. 20 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 21 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 22 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 23 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 24 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 25 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 26 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 27 is a cross-sectional view of a microphone package of the presentinvention with a retaining ring;

FIG. 28 is a cross-sectional view of a microphone package of the presentinvention with a retaining wing;

FIG. 29 is a cross-sectional view of a microphone package of the presentinvention with a retaining ring;

FIG. 30 is a plan view of a panel of a plurality of microphone packages;and

FIG. 31 is a plan view of a microphone pair.

DETAILED DESCRIPTION

While the invention is susceptible of embodiments in many differentforms, there is shown in the drawings and will herein be described indetail several possible embodiments of the invention with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the broad aspect of the invention to the embodimentsillustrated.

The present invention is directed to microphone packages. The benefitsof the microphone packages disclosed herein over microphone packagingutilizing plastic body/lead frames include the ability to processpackages in panel form allowing more units to be formed per operationand at much lower cost. The typical lead frame for a similarlyfunctioning package would contain between 40 and 100 devices connectedtogether. The present disclosure would have approximately 14,000 devicesconnected together (as a panel). Also, the embodiments disclosed hereinrequire minimal “hard-tooling” This allows the process to adjust tocustom layout requirements without having to redesign mold, lead frame,and trim/form tooling.

Moreover, many of the described embodiments have a better match ofthermal coefficients of expansion with the end user's PCB, typicallymade of FR-4, since the microphone package is also made primarily ofFR-4. These embodiments of the invention may also eliminate the need forwire bonding that is required in plastic body/lead frame packages. Thefootprint is typically smaller than that would be required for a plasticbody/lead frame design since the leads may be formed by plating athrough-hole in a circuit board to form the pathway to the solder pad.In a typical plastic body/lead frame design, a (gull wing configurationwould be used in which the leads widen the overall foot print.

Now, referring to FIGS. 1-3, three embodiments of a silicon condensermicrophone package 10 of the present invention are illustrated. Includedwithin silicon microphone package 10 is a transducer 12, e.g. a siliconcondenser microphone as disclosed in U.S. Pat. No. 5,870,482 which ishereby incorporated by reference and an amplifier 16. The package itselfincludes a substrate 14, a back volume or air cavity 18, which providesa pressure reference for the transducer 12, and a cover 20. Thesubstrate 14 may be formed of FR-4 material allowing processing incircuit board panel form, thus taking advantage of economies of scale inmanufacturing. FIG. 6 is a plan view of the substrate 14 showing theback volume 18 surrounded a plurality of terminal pads.

The back volume 18 may be formed by a number of methods, includingcontrolled depth drilling of an upper surface 19 of the substrate 14 toform a recess over which the transducer 12 is mounted (FIG. 1); drillingand routing of several individual sheets of FR-4 and laminating theindividual sheets to form the back volume 18, which may or may not haveinternal support posts (FIG. 2); or drilling completely through thesubstrate 14 and providing a sealing ring 22 on the bottom of the devicethat will seal the back volume 18 during surface mounting to a user's“board” 28 (FIGS. 3-5). In this example, the combination of thesubstrate and the user's board 28 creates the back volume 18. The backvolume 18 is covered by the transducer 12 (e.g., a MEMS device) whichmay be “bumpbonded” and mounted face down. The boundary is sealed suchthat the back volume 18 is operably “air-tight.”

The cover 20 is attached for protection and processability. The cover 20contains an aperture 24 which may contain a sintered metal insert 26 toprevent water, particles and/or light from entering the package anddamaging the internal components inside; i.e. semiconductor chips. Theaperture 24 is adapted for allowing sound waves to reach the transducer12. The sintered metal insert 26 will also have certain acousticproperties, e.g. acoustic damping or resistance. The sintered metalinsert 26 may therefore be selected such that its acoustic propertiesenhance the functional capability of the transducer 12 and/or theoverall performance of the silicon microphone 10.

Referring to FIGS. 4 and 5 the final form of the product is a siliconcondenser microphone package 10 which would most likely be attached toan end user's PCB 28 via a solder reflow process. FIG. 5 illustrates amethod of enlarging the back volume 18 by including a chamber 32 withinthe end user's circuit board 28.

Another embodiment of a silicon condenser microphone package 40 of thepresent invention is illustrated in FIGS. 7-10. In this embodiment, ahousing 42 is formed from layers of materials, such as those used inproviding circuit boards. Accordingly, the housing 42 generallycomprises alternating layers of conductive and non-conductive materials44, 46. The non-conductive layers 46 are typically FR-4 board. Theconductive layers 44 are typically copper. This multi-layer housingconstruction advantageously permits the inclusion of circuitry, powerand ground planes, solder pads, ground pads, capacitance layers andplated through holes pads within the structure of the housing itself.The conductive layers provide EMI shielding while also allowingconfiguration as capacitors and/or inductors to filter input/outputsignals and/or the input power supply.

In the embodiment illustrated, the housing 42 includes a top portion 48and a bottom portion 50 spaced by a side portion 52. The housing 42further includes an aperture or acoustic port 54 for receiving anacoustic signal and an inner chamber 56 which is adapted for housing atransducer unit 58, typically a silicon die microphone or a ball gridarray package (BGA). The top, bottom, and side portions 48, 50, 52 areelectrically connected, for example with a conductive adhesive 60. Theconductive adhesive may be provided conveniently in the form of suitablyconfigured sheets of dry adhesive disposed between the top, bottom andside portions 48, 50 and 52. The sheet of dry adhesive may be activatedby pressure, heat or other suitable means after the portions are broughttogether during assembly. Each portion may comprise alternatingconductive and non-conductive layers of 44, 46.

The chamber 56 may include an inner lining 61. The inner lining 61 isprimarily formed by conductive material. It should be understood thatthe inner lining may include portions of non-conductive material, as theconductive material may not fully cover the non-conductive material. Theinner lining 61 protects the transducer 58 against electromagneticinterference and the like, much like a faraday cage. The inner lining 61may also be provided by suitable electrically coupling together of thevarious conductive layers within the top, bottom and side portions 48,50 and 52 of the housing.

In the various embodiments illustrated in FIGS. 7-10 and 23-26, theportions of the housing 42 that include the aperture or acoustic port 54further include a layer of material that forms an environmental barrier62 over or within the aperture 54. This environmental barrier 62 istypically a polymeric material formed to a film, such as apolytetrafluoroethylene (PTFE) or a sintered metal. The environmentalbarrier 62 is supplied for protecting the chamber 56 of the housing 42,and, consequently, the transducer unit 58 within the housing 42, fromenvironmental elements such as sunlight, moisture, oil, dirt, and/ordust. The environmental barrier 62 will also have inherent acousticproperties, e.g. acoustic damping/resistance. Therefore theenvironmental barrier 62 is chosen such that its acoustic propertiescooperate with the transducer unit 58 to enhance the performance of themicrophone. This is particularly true in connection with the embodimentsillustrated in FIGS. 24 and 25, which may be configured to operate asdirectional microphones.

The environmental barrier layer 62 is generally sealed between layers ofthe portion, top 48 or bottom 50 in which the acoustic port 54 isformed. For example, the environmental barrier may be secured betweenlayers of conductive material 44 thereby permitting the layers ofconductive material 44 to act as a capacitor (with electrodes defined bythe metal) that can be used to filter input and output signals or theinput power. The environmental barrier layer 62 may further serve as adielectric protective layer when in contact with the conductive layers44 in the event that the conductive layers also contain thin filmpassive devices such as resistors and capacitors.

In addition to protecting the chamber 56 from environmental elements,the barrier layer 62 allows subsequent wet processing, board washing ofthe external portions of the housing 42, and electrical connection toground from the walls via thru hole plating. The environmental barrierlayer 62 also allows the order of manufacturing steps in the fabricationof the printed circuit board-based package to be modified. Thisadvantage can be used to accommodate different termination styles. Forexample, a double sided package can be fabricated having a pair ofapertures 54 (see FIG. 25), both including an environmental barrierlayer 62. The package would look and act the same whether it is mountedface up or face down, or the package could be mounted to providedirectional microphone characteristics. Moreover, the environmentalbarrier layer 62 may also be selected so that its acoustic propertiesenhance the directional performance of the microphone.

Referring to FIGS. 7, 8, and 11-13 the transducer unit 58 is generallynot mounted to the top portion 48 of the housing. This definition isindependent of the final mounting orientation to an end user's circuitboard. It is possible for the top portion 48 to be mounted face downdepending on the orientation of the transducer 58 as well as the choicefor the bottom portion 50. The conductive layers 44 of the top portion48 may be patterned to form circuitry, ground planes, solder pads,ground pads, capacitors and plated through hole pads. Referring to FIGS.1-13 there may be additional alternating conductive layers 44,non-conductive layers 46, and environmental protective membranes 62 asthe package requires. Alternatively, some layers may be deliberatelyexcluded as well. The first non-conductive layer 46 may be patterned soas to selectively expose certain features on the first conductive layer44.

FIG. 11 illustrates an alternative top portion 48 for a microphonepackage. In this embodiment, a connection between the layers can beformed to provide a conduit to ground. The top portion of FIG. 11includes ground planes and/or pattern circuitry 64 and the environmentalbarrier 62. The ground planes and or pattern circuitry 64 are connectedby pins 65.

FIG. 12 illustrates another embodiment of a top portion 48. In additionto the connection between layers, ground planes/pattern circuitry 64,and the environmental barrier 62, this embodiment includes conductivebumps 66 (e.g. Pb/Sn or Ni/Au) patterned on the bottom side to allowsecondary electrical contact to the transducer 58. Here, conductivecircuitry would be patterned such that electrical connection between thebumps 66 and a plated through hole termination is made.

FIG. 13 illustrates yet another embodiment of the top portion 48. Inthis embodiment, the top portion 48 does not include an aperture oracoustic port 54.

Referring to FIGS. 7, 8 and 14-18, the bottom portion 50 is thecomponent of the package to which the transducer 58 is primarilymounted. This definition is independent of the final mountingorientation to the end user's circuit board. It is possible for thebottom portion 50 to be mounted facing upwardly depending on themounting orientation of the transducer 58 as well as the choice for thetop portion 48 construction Like the top portion 48, the conductivelayers 44 of the bottom portion 50 may be patterned to form circuitry,ground planes, solder pads, ground pads, capacitors and plated throughhole pads. As shown in FIGS. 14-18, there may be additional alternatingconductive layers 44, non-conductive layers 46, and environmentalprotective membranes 62 as the package requires. Alternatively, somelayers may be deliberately excluded as well. The first non-conductivelayer 46 may be patterned so as to selectively expose certain featureson the first conductive layer 44.

Referring to FIGS. 14 a through 14 d, the bottom portion 50 comprises alaminated, multi-layered board including layers of conductive material44 deposited on layers of non-conductive material 46. Referring to FIG.14 b, the first layer of conductive material is used to attach wirebonds or flip chip bonds. This layer includes etched portions to definelead pads, bond pads, and ground pads. The pads would have holes drilledthrough them to allow the formation of plated through-holes.

As shown in FIG. 14 c, a dry film 68 of non-conductive material coversthe conductive material. This illustration shows the exposed bondingpads as well as an exposed ground pad. The exposed ground pad would comein electrical contact with the conductive epoxy and form the connectionto ground of the side portion 52 and the base portion 50.

Referring to FIG. 14 d, ground layers can be embedded within the baseportion 50. The hatched area represents a typical ground plane 64. Theground planes do not overlap the power or output pads, but will overlapthe transducer 58.

Referring to FIG. 15, an embodiment of the bottom portion 50 isillustrated. The bottom portion 50 of this embodiment includes a soldermask layer 68 and alternating layers of conductive and non-conductivematerial 44, 46. The bottom portion further comprises solder pads 70 forelectrical connection to an end user's board.

FIGS. 16 and 17 illustrate embodiments of the bottom portion 50 withenlarged back volumes 18. These embodiments illustrate formation of theback volume 18 using the conductive/non-conductive layering.

FIG. 18 shows yet another embodiment of the bottom portion 50. In thisembodiment, the back portion 50 includes the acoustic port 54 and theenvironmental barrier 62.

Referring to FIGS. 7-10 and 19-22, the side portion 52 is the componentof the package that joins the bottom portion 50 and the top portion 48.The side portion 52 may include a single layer of a non-conductivematerial 46 sandwiched between two layers of conductive material 44. Theside portion 52 forms the internal height of the chamber 56 that housesthe transducer 58. The side portion 52 is generally formed by one ormore layers of circuit board material, each having a routed window 72(see FIG. 19).

Referring to FIGS. 19-22, the side portion 52 includes inner sidewalls74. The inner sidewalls 74 are generally plated with a conductivematerial, typically copper, as shown in FIGS. 20 and 21. The sidewalls74 are formed by the outer perimeter of the routed window 72 andcoated/metallized with a conductive material.

Alternatively, the sidewalls 74 may be formed by may alternating layersof non-conductive material 46 and conductive material 44, each having arouted window 72 (see FIG. 19). In this case, the outer perimeter of thewindow 72 may not require coverage with a conductive material becausethe layers of conductive material 44 would provide effective shielding.

FIGS. 23-26 illustrate various embodiments of the microphone package 40.These embodiments utilize top, bottom, and side portions 48, 50, and 52which are described above. It is contemplated that each of the top,bottom, and side portion 48, 50, 52 embodiments described above can beutilized in any combination without departing from the inventiondisclosed and described herein.

In FIG. 23, connection to an end user's board is made through the bottomportion 50. The package mounting orientation is bottom portion 50 down.Connection from the transducer 58 to the plated through holes is be madeby wire bonding. The transducer back volume 18 is formed by the backhole (mounted down) of the silicon microphone only. Bond pads, wirebonds and traces to the terminals are not shown. A person of ordinaryskilled in the art of PCB design will understand that the traces resideon the first conductor layer 44. The wire bonds from the transducer 58are be connected to exposed pads. The pads are connected to the solderpads via plated through holes and traces on the surface.

In FIG. 24, connection to the end user's board is also made through thebottom portion 50. Again, the package mounting orientation is bottomportion 50. Connection from the transducer 58 to the plated throughholes are made by wire bonding. The back volume is formed by acombination of the back hole of the transducer 58 (mounted down) and thebottom portion 50.

In FIG. 25, connection to the end user's board is also made through thebottom portion 50. Again, the package mounting orientation is bottomportion 50. Connection from the transducer 58 to the plated throughholes are made by wire bonding. With acoustic ports 54 on both sides ofthe package, there is no back volume. This method is suitable to adirectional microphone.

In FIG. 26, connection to the end user's board is made through the topportion 48 or the bottom portion 53. The package mounting orientation iseither top portion 48 down or bottom portion 50 down. Connection fromthe transducer 58 to the plated through holes is made by flip chippingor wire bonding and trace routing. The back volume 18 is formed by usingthe air cavity created by laminating the bottom portion 50 and the topportion 48 together. Some portion of the package fabrication isperformed after the transducer 58 has been attached. In particular, thethrough hole formation, plating, and solder pad definition would be doneafter the transducer 58 is attached. The protective membrane 62 ishydrophobic and prevents corrosive plating chemistry from entering thechamber 56.

Referring to FIGS. 27-29, the portion to which the transducer unit 58 ismounted may include a retaining ring 84. The retaining ring 84 preventswicking of an epoxy 86 into the transducer 58 and from flowing into theacoustic port or aperture 54. Accordingly, the shape of the retainingring 84 will typically match the shape of the transducer 58 foot print.The retaining ring 84 comprises a conductive material (e.g., 3 mil.thick copper) imaged on a non-conductive layer material.

Referring to FIG. 27, the retaining ring 84 is imaged onto anonconductive layer. An epoxy is applied outside the perimeter of theretaining ring 84, and the transducer 58 is added so that it overlapsthe epoxy 86 and the retaining ring 84. This reduces epoxy 86 wicking upthe sides of the transducer's 58 etched port (in the case of a silicondie microphone).

Alternatively, referring to FIG. 28, the retaining ring 84 can belocated so that the transducer 58 does not contact the retaining ring84. In this embodiment, the retaining ring 84 is slightly smaller thanthe foot print of the transducer 58 so that the epoxy 86 has arestricted path and is, thus, less likely to wick. In FIG. 29, theretaining ring 84 is fabricated so that it contacts the etched port ofthe transducer 58. The following tables provide an illustrative exampleof a typical circuit board processing technique for fabrication of thehousing of this embodiment.

TABLE 1 Materials Material Type Component Note 1 0.5/0.5 oz. DST BottomPortion Cu 5 core FR-4 (Conductive Layers Non-Conductive Layer 1) 20.5/0.5 oz. DST Bottom Portion Cu 5 core FR-4 (Conductive Layers 3 and4; Non-Conductive Layer 2) 3 106 pre-preg For Laminating Material 1 andMaterial 2 4 0.5/0.5 oz. DST Side Portion Metallized Cu 40 Core FR-4Afterward 5 Bare/0.5 oz. Cu 2 Top Portion (Each core FR-4 (2 PieceIncludes 1 pieces) Conductive and 1 Non-Conductive Layer) 6 ExpandedPTFE Environmental Barrier

TABLE 2 Processing of Materials (Base Portion Material 1) Step TypeDescription Note 1 Dry Film Conductive Layers 2 Expose Mask Material 1(Upper Forms Ground Conductive Layer) Plane on Lower Conductive Layer 3Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film

TABLE 3 Processing of Materials (Bottom Portion Material 2) Step TypeDescription Note 1 Dry Film Conductive Layers 2 Expose Mask Material 2Forms Ground (Upper Conductive Plane on Upper Layer) Conductive Layer 3Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film

TABLE 4 Processing of Materials 1, 2, and 3 (Form Bottom Portion) StepType Description Note  1 Laminate Materials 1 and 2 Laminated UsingMaterial 3  2 Drill Thru Holes Drill Bit = 0.025 in.  3 Direct PlatesThru Holes Metallization/Flash Copper  4 Dry Film (L1 and L4)  5 ExposeMask Laminated Forms Traces and Materials 1 and 2 Solder Pads (Upper andLower Conductive Layers)  6 Develop  7 Electrolytic Cu 1.0 mil  8Electrolytic Sn As Required  9 Strip Dry Film 10 Etch Cu 11 Etch Cu 12Insert Finishing NG Option (See NG Option for Proof Option Here TableBelow) of Principle 13 Dry Film (cover 2.5 mil Minimum Thickness lay) onUpper on Upper Conductive Conductive Layer Layer Only 14 Expose MaskLaminated This mask defines an Materials 1 and 2 area on the upper(upper and lower) conductive layer that will receive a dry film soldermask (cover lay). The bottom layer will not have dry film applied to it.The plated through holes will be bridged over by the coating on the top.15 Develop 16 Cure Full Cure 17 Route Panels Route Bit = As Forms 4″ ×4″ pieces. Required Conforms to finished dims

Table 5 describes the formation of the side portion 52. This processinvolves routing a matrix of openings in FR-4 board. However, punchingis thought to be the cost effective method for manufacturing. Thepunching may done by punching through the entire core, or,alternatively, punching several layers of no-flow pre-preg and thin corec-stage which are then laminated to form the wall of proper thickness.

After routing the matrix, the board will have to be electroless or DMplated. Finally, the boards will have to be routed to match the bottomportion. This step can be done first or last. It may make the piece moreworkable to perform the final routing as a first step.

TABLE 5 Processing of Material 4 (Side Portion) Step Type DescriptionNote 1 Route/Punch Route Bit = 0.031 in. Forms Side Portion Matrix ofOpenings 2 Direct 0.25 mil minimum Forms Sidewalls Metallization/ onSide Portion Flash Cu 3 Route Panels

Table 6 describes the processing of the top portion. The formation ofthe top portion 48 involves imaging a dry film cover lay or liquidsolder mask on the bottom (i.e. conductive layer forming the innerlayer. The exposed layer of the top portion 48 will not have a coppercoating. It can be processed this way through etching or purchased thisway as a one sided laminate.

A matrix of holes is drilled into the lid board. Drilling may occurafter the imaging step. If so, then a suitable solder mask must bechosen that can survive the drilling process.

TABLE 6 Processing of Top Portion Step Type Description Note 1 Dry FilmConductive Layer 2 Expose Mask Bare Layer Form Conduction Ring 3 Develop4 Cure 5 Drill Matrix Drill Bit 0.025 in. Acoustic Ports of Holes 6Laminate PTFE (Environmental Forms Top Barrier) Between 2 Pieces Portionof Material 5

TABLE 7 Processing of Laminated Materials 1 and 2 with Material 4 StepType Description Note 1 Screen Conductive Adhesive on Material 4 2Laminate Bottom Portion with Forms Bottom Side Portion Portion with SidePortion (spacer) 3 Add Transducer Silicon Die Microphone Assembly andIntegrated Circuit

TABLE 8 Processing of Laminated Materials 1, 2, and 4 with Material 5Step Type Description Note 1 Screen Conductive Adhesive on Top Portion 2Laminate Bottom Portion and Side Forms Portion with Top Portion Housing3 Dice

TABLE 9 Finishing Option NG (Nickel/Gold) Step Type Description Note 1Immersion Ni (40-50 μ-in) 2 Immersion Au (25-30 μ-in)

TABLE 10 Finishing Option NGT (Nickel/Gold/Tin) Step Type 1 Mask L2(using thick dry film or high tack dicing tape) 2 Immersion Ni (40-50μ-in) 3 Immersion Au (25-30 μ-in) 4 Remove Mask on L2 5 Mask L1 (usingthick dry film or high tack dicing tape) bridge over cavity created bywall 6 Immersion Sn (100-250 μ-in) 7 Remove Mask on L1

TABLE 11 Finishing Option ST (Silver/Tin) Step Type 1 Mask L2 (usingthick dry film or high tack dicing tape) 2 Immersion Ag (40-50 μ-in) 3Remove Mask on L2 4 Mask L1 (using thick dry film or high tack dicingtape) bridge over cavity created by wall 5 Immersion Sn (100-250 μ-in) 6Remove Mask on L1

FIG. 30 is a plan view illustrating a panel 90 for forming a pluralityof microphone packages 92. The microphone packages 92 are distributed onthe panel 90 in a 14×24 array, or 336 microphone packages total. Feweror more microphone packages may be disposed on the panel 90, or onsmaller or larger panels. As described herein in connection with thevarious embodiments of the invention, the microphone packages include anumber of layers, such as top, bottom and side portions of the housing,environmental barriers, adhesive layers for joining the portions, andthe like. To assure alignment of the portions as they are broughttogether, each portion may be formed to include a plurality of alignmentapertures 94. To simultaneously manufacture several hundred or evenseveral thousand microphones, a bottom layer, such as described herein,is provided. A transducer, amplifier and components are secured atappropriate locations on the bottom layer corresponding to each of themicrophones to be manufactured. An adhesive layer, such as a sheet ofdry adhesive is positioned over the bottom layer, and a sidewall portionlayer is positioned over the adhesive layer. An additional dry adhesivelayer is positioned, followed by an environmental barrier layer, anotherdry adhesive layer and the top layer. The dry adhesive layers areactivated, such as by the application of heat and/or pressure. The panelis then separated into individual microphone assemblies using knownpanel cutting and separating techniques.

The microphone, microphone package and method of assembly hereindescribed further allow the manufacture of multiple microphone assembly,such as microphone pairs. In the simplest form, during separation twomicrophones may be left joined together, such as the microphone pair 96shown in FIG. 31. Each microphone 98 and 100 of the microphone pair 96is thus a separate, individually operable microphone in a single packagesharing a common sidewall 102. Alternatively, as described herein,conductive traces may be formed in the various layers of either the topor bottom portion thus allowing multiple microphones to be electricallycoupled.

While specific embodiments have been illustrated and described, numerousmodifications come to mind without significantly departing from thespirit of the invention, and the scope of protection is only limited bythe scope of the accompanying Claims.

What is claimed is:
 1. A method for manufacturing a plurality of solderreflow surface mount microelectromechanical system (MEMS) microphones,the method comprising: providing an unsingulated panel comprised of aplurality of individual rectangular substrates, each rectangularsubstrate including: a rigid base layer comprised of multiple sub-layersof non-conductive material, each sub-layer having a predeterminedcoefficient of thermal expansion, wherein the base layer has a planartop surface and a planar bottom surface, the top surface having aninterior region and an attachment region, the attachment region disposedbetween the interior region and the edges of the base layer, andcompletely bounding the interior region; a first plurality of metal padsdisposed on the top surface of the base layer and defined by a firstsolder mask layer; a second plurality of flat metal pads disposed on thebottom surface of the base layer and defined by a second solder masklayer, the second plurality of metal pads arranged to be within aperimeter of the bottom surface of the base layer; and one or moreelectrical pathways disposed completely within the base layer, whereinthe pathways electrically couple one or more of the first plurality ofmetal pads on the top surface of the base layer to one or more of thesecond plurality of metal pads on the bottom surface of the base layer;mounting a MEMS microphone die to the top surface of each individualsubstrate in the panel of unsingulated substrates, and electricallycoupling the MEMS microphone die to at least one of the first pluralityof metal pads on the top surface of its respective substrate; providinga plurality of single-piece rectangular covers, wherein each rectangularcover is formed from a solid material and has a predetermined shape thatcomprises a top portion, and a substantially vertical and continuoussidewall portion that adjoins the top portion at an angle and thatcompletely surrounds and supports the top portion, the sidewall portionhaving a predetermined height, an exterior sidewall surface, an interiorsidewall surface, and an attachment surface, wherein each single-piecerectangular cover further comprises an acoustic port disposed in the topportion of the rectangular cover and passing completely through therectangular cover, wherein the acoustic port is disposed in a positionoffset from a centerpoint of the top portion of the rectangular cover;attaching one rectangular cover to each substrate of the panel ofunsingulated substrates having a MEMS microphone die mounted thereon,wherein the attachment surface of the sidewall portion of therectangular cover being attached is aligned with and attached to theattachment region of the top surface of its respective individualsubstrate, and wherein the predetermined height of the sidewall portionof the rectangular cover, the interior surface of the sidewall portionof the rectangular cover, and an interior surface of the top portion ofthe rectangular cover, in cooperation with the interior region of thetop surface of its respective individual substrate, define an acousticchamber for its respective MEMS microphone die and provide a protectiveenclosure for its respective MEMS microphone die to reduceelectromagnetic interference; and singulating the substrate panel intodiscrete surface mount MEMS microphones.
 2. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 1,wherein, for one or more of the substrates of the panel of unsingulatedsubstrates, at least one passive electrical element is electricallycoupled between one of the first plurality of metal pads and one of thesecond plurality of metal pads.
 3. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 2,wherein, for each individual substrate of the panel of unsingulatedsubstrates that includes at least one passive electrical element, the atleast one passive electrical element is disposed within the base layerof the individual substrate.
 4. A method for manufacturing a pluralityof surface mount MEMS microphones according to claim 3, wherein, foreach individual substrate of the panel of unsingulated substrates thatincludes at least one passive electrical element, the at least onepassive electrical element includes a dielectric or resistive materialthat is different from the sub-layers of non-conductive material in thebase layer of the individual substrate.
 5. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 2,wherein, for each individual substrate in the panel of unsingulatedsubstrates, the at least one passive electrical element is configured tofilter one or more of an input signal, an output signal, or input power.6. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 1, wherein, for one or more of theplurality of individual rectangular covers, the rectangular coverfurther comprises an acoustic material that substantially blockscontaminants from entering the acoustic chamber through the acousticport.
 7. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 1, wherein, for one or more of thesubstrates of the panel of unsingulated substrates, one or moresub-layers of the base layer include FR-4 printed circuit boardmaterial.
 8. A method for manufacturing a plurality of surface mountMEMS microphones according to claim 1, wherein, for each individualmicrophone, the enclosure protects the MEMS microphone die from at leastone of light and physical damage.
 9. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 1,wherein, for each individual microphone, a diaphragm of the MEMSmicrophone die defines a front volume and a back volume within theacoustic chamber, and the acoustic port disposed in the rectangularcover is acoustically coupled to the diaphragm by the front volume. 10.A method for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 9, wherein, for each individual microphone, theinterface between the attachment surface of the sidewall portion of therectangular cover and the attachment region of the top surface of thesubstrate is sealed to maintain acoustic pressure within the frontvolume.
 11. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 1, wherein the MEMS microphone die is apressure-equalizing MEMS microphone die.
 12. A method for manufacturinga plurality of surface mount MEMS microphones according to claim 1,wherein, for each individual microphone, the acoustic port in therectangular cover is a first acoustic port, and the base layer of thesubstrate further comprises a second acoustic port disposed in theinterior region of the base layer and passing completely through thebase layer, wherein the second acoustic port is disposed in a positionoffset from a centerpoint of the substrate, and wherein one of thesecond plurality of metal pads is a metal ring that completely surroundsthe second acoustic port in the base layer.
 13. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 12, wherein, for each individual substrate in the panel ofunsingulated substrates, the second acoustic port further comprises abarrier that substantially blocks contaminants from entering theacoustic chamber through the second acoustic port.
 14. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 13, wherein, for each individual substrate in the panel ofunsingulated substrates, the barrier is a film of polymeric material.15. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 13, wherein, for each individualsubstrate in the panel of unsingulated substrates, the barrier is ahydrophobic material.
 16. A method for manufacturing a plurality ofsurface mount MEMS microphones according to claim 12, wherein, for eachindividual MEMS microphone, the MEMS microphone die is positioned overthe second acoustic port in the base layer.
 17. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 1, wherein, for each individual substrate in the panel ofunsingulated substrates, the base layer further comprises a recessdisposed therein, and the MEMS microphone die is positioned over therecess.
 18. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 1, wherein, for each individual substratein the panel of unsingulated substrates, the base layer furthercomprises an internal cavity with an aperture in the top surface of thebase layer, and the MEMS microphone die is positioned over the aperturein the top surface of the base layer.
 19. A method for manufacturing aplurality of solder reflow surface mount microelectromechanical system(MEMS) microphones, the method comprising: providing an unsingulatedpanel of rectangular base portions, each individual rectangular baseportion including: a rigid base layer comprised of comprised of multiplesub-layers of printed circuit board material, each sub-layer having apredetermined coefficient of thermal expansion, wherein the base layerhas a substantially flat upper surface and a substantially flat lowersurface, the upper surface having an inner area and a coupling area, thecoupling area located between the inner area and the edges of the baselayer, and completely surrounding the inner area; a plurality of metalpads located on the upper surface of the base layer and defined by afirst solder mask; a plurality of flat solder pads located on the lowersurface of the base layer and defined by a second solder mask layer, theplurality of solder pads arranged to be within a perimeter of the lowersurface of the base layer; one or more electrical connections passingthrough the base layer, wherein the connections electrically couple oneor more of the plurality of metal pads on the upper surface of the baselayer to one or more of the plurality of solder pads on the lowersurface of the base layer; and at least one passive electrical elementdisposed within the base layer and electrically coupled between one ofthe plurality of metal pads and one of the plurality of solder pads;mounting a MEMS microphone die to the upper surface of each individualbase portion in the unsingulated panel of base portions, andelectrically coupling each MEMS microphone die to at least one of theplurality of metal pads on the upper surface of the base layer of itsrespective base portion; and providing a plurality of rectangular coverportions, each rectangular cover portion formed from a single piece ofsolid material and having a predetermined shape, each rectangular coverportion having a top portion and a substantially vertical and continuoussidewall portion that adjoins the top portion at an angle and thatcompletely surrounds and supports the top portion, the sidewall portionhaving a predetermined height, an exterior surface, an interior surface,and a coupling surface, wherein each rectangular cover further comprisesan acoustic port disposed in the top portion of the rectangular coverand passing completely through the rectangular cover, wherein theacoustic port is disposed in a position offset from a centerpoint of thetop portion of the rectangular cover; coupling one rectangular coverportion to each base portion of the panel of unsingulated base portionshaving a MEMS microphone die mounted thereon, wherein the couplingsurface of the sidewall portion of the cover portion being coupled isaligned with and mechanically coupled to the coupling area of the baselayer of its respective base portion; wherein the predetermined heightof the sidewall portion of the cover portion, the interior surface ofthe sidewall portion of the cover portion, and the interior surface ofthe top portion of the cover portion, in cooperation with the interiorregion of the upper surface of the base layer of its respective baseportion, define an acoustic chamber for the MEMS microphone die andprovide a protective enclosure for its respective MEMS microphone die;and wherein the overall length of base portions having a MEMS microphonedie mounted thereon and their respective cover portions aresubstantially equal, and the overall width of the base portions having aMEMS microphone die mounted thereon and their respective cover portionsare substantially equal; and singulating the panel of base portions intodiscrete surface mount MEMS microphones.
 20. A solder reflow surfacemount MEMS microphone according to claim 19, wherein, for eachindividual base portion in the panel of unsingulated base portions, theat least one passive electrical element comprises a dielectric orresistive material that is different from the non-conductive material inthe base layer of the base portion.
 21. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 19,wherein, for each individual MEMS microphone, the enclosure protects theMEMS microphone die from at least one of light, electromagneticinterference, and physical damage.
 22. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 19,wherein, for each individual rectangular cover portion, the rectangularcover portion further comprises an acoustic material that substantiallyblocks contaminants from entering the acoustic chamber through theacoustic port.
 23. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 19, wherein, for eachindividual MEMS microphone, a diaphragm of the MEMS microphone diedefines a front volume and a back volume within the acoustic chamber,and the acoustic port disposed in the top portion of the cover portionis acoustically coupled to the diaphragm; and wherein the interfacebetween the coupling surface of the sidewall portion of the coverportion and the coupling area of the upper surface of the base layer ofthe base portion is sealed to maintain acoustic pressure within thefront volume.
 24. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 19, wherein, for eachindividual microphone, the acoustic port in the rectangular coverportion is a first acoustic port, and the base portion further comprisesa second acoustic port located in the inner area of the base layer andpassing completely through the base layer, wherein the second acousticport is disposed in a position offset from a centerpoint of the baseportion, wherein one of the second plurality of solder pads is a solderpad ring that completely surrounds the second acoustic port in the baselayer, and wherein the MEMS microphone die is positioned over the secondacoustic port.
 25. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 24, wherein, for eachindividual base portion in the panel of unsingulated base portions, thesecond acoustic port further comprises a barrier of polymeric materialthat substantially blocks contaminants from entering the acousticchamber through the second acoustic port.
 26. A method for manufacturinga plurality of surface mount MEMS microphones according to claim 24,wherein, for each individual base portion in the panel of unsingulatedbase portions, the second acoustic port further comprises a barrier ofhydrophobic material that substantially blocks contaminants fromentering the acoustic chamber through the second acoustic port.
 27. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 19, wherein, for each individual base portion in thepanel of unsingulated base portions, the at least one passive electricalelement is configured to filter one or more of an input signal, anoutput signal, or input power.
 28. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 19,wherein, for each individual base portion in the panel of unsingulatedbase portions, the at least one passive electrical element comprises adielectric or resistive material that is different from the printedcircuit board material in the base layer of the base portion.
 29. Amethod for manufacturing a plurality of solder reflow surface mountmicroelectromechanical system (MEMS) microphones, the method comprising:providing an unsingulated panel comprising a plurality of rectangularbase elements, each individual base element including: a rigid corelayer comprised of multiple sub-layers of FR-4 printed circuit boardmaterial, each sub-layer having a predetermined coefficient of thermalexpansion, wherein the core layer has a substantially flat top surfaceand a substantially flat bottom surface, the top surface having a diemount region and an attachment region, the attachment region positionedbetween the die mount region and the edges of the core layer, andcompletely surrounding the die mount region; a plurality of metal padslocated on the top surface of the core layer and defined by a firstsolder mask; a plurality of flat solder pads located on the bottomsurface of the core layer and defined by a second solder mask, theplurality of solder pads arranged to be within a perimeter of the bottomsurface of the core layer, wherein the solder pads are plated with atleast one metal; a plurality of electrical connections passing throughthe core layer that electrically couple one or more of the plurality ofmetal pads on the top surface of the core layer to one or more of theplurality of solder pads on the bottom surface of the core layer; and atleast one passive electrical element disposed within the core layer andelectrically coupled between one of the plurality of metal pads and oneof the plurality of solder pads; and a pressure-equalizing MEMSmicrophone die having an internal acoustic channel mounted in the diemount region of the core layer, and electrically coupled to one or moreof the metal pads on the top surface of the core layer; providing aplurality of single-piece rectangular cover elements formed from a solidmaterial and having a predetermined shape, each rectangular coverelement having a top region and a continuous wall region, the continuouswall region supporting the top region and adjoining the top region at asubstantially perpendicular angle and having a predetermined height, anexterior surface, an interior surface, and an attachment surface, and anacoustic port located in the top region of the cover element and passingcompletely through the top region, wherein the acoustic port is disposedin a position offset from a centerpoint of the cover element; coupling arectangular cover element to each base element of the panel ofunsingulated base elements, one cover element to each individual baseelement, wherein each cover element is coupled to its respective baseelement such that the attachment surface of the wall region of the coverelement is aligned with and physically coupled to the attachment regionof the top surface of the core layer of its respective base element,thereby forming a protective enclosure for its respective MEMSmicrophone die; wherein the interior of the protective enclosure is anacoustic chamber having a volume defined by the predetermined height ofwall region of the cover element, and the width and length of the topregion of the cover element; wherein a diaphragm of the MEMS microphonedie defines a front volume and a back volume within its respectiveacoustic chamber, and the acoustic port disposed in the cover element isacoustically coupled to the diaphragm; and wherein the interface betweenthe attachment surface of the continuous wall region of cover elementand the attachment area of the top surface of the core layer of the baseelement is sealed to prevent the escape of acoustic pressure from thefront volume; and singulating the panel of base elements into discretesurface mount MEMS microphones.
 30. A solder reflow surface mount MEMSmicrophone according to claim 29, wherein, for each individual baseelement in the panel of unsingulated base elements, the at least onepassive electrical element comprises a dielectric or resistive materialthat is different from the FR-4 printed circuit board material in thecore layer of the base element.
 31. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 29,wherein, for each individual MEMS microphone, the enclosure protects theMEMS microphone die from at least one of light, electromagneticinterference, and physical damage.
 32. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 29,wherein for each individual cover element, the cover element furthercomprises an acoustic material that substantially blocks contaminantsfrom entering the acoustic chamber through the acoustic port.
 33. Asolder reflow surface mount MEMS microphone according to claim 29,wherein, for each individual base element in the panel of unsingulatedbase elements, the core layer of the base element further comprises aninternal cavity with an aperture in the top surface of the core layer,and the MEMS microphone die is positioned over the aperture in the topsurface of the core layer.
 34. A method for manufacturing a plurality ofsurface mount MEMS microphones according to claim 29, wherein, for eachindividual base element in the panel of unsingulated base elements, theat least one passive electrical element is configured to filter one ormore of an input signal, an output signal, or input power.
 35. A methodfor manufacturing a plurality of surface mount MEMS microphonesaccording to claim 29, wherein, for each individual base element in thepanel of unsingulated base elements, the at least one passive electricalelement comprises a dielectric or resistive material that is differentfrom the printed circuit board material in the core layer of the baseelement.
 36. A method for manufacturing a plurality of solder reflowsurface mount microelectromechanical system (MEMS) microphones, themethod comprising: providing a plurality of pressure-equalizing MEMSmicrophone die, each having an internal acoustic channel; providing anunsingulated panel that includes a plurality of first housing elementseach having a rectangular shape, the first housing elements furtherincluding: a rigid core layer comprised of multiple layers of FR-4printed circuit board material, each layer of FR-4 material having apredetermined coefficient of thermal expansion, wherein the core layerhas a substantially flat top surface and a substantially flat bottomsurface, wherein the top surface has an die mount region and anattachment region, the attachment region being arranged between the diemount region and the edges of the core layer, and the attachment regioncompletely surrounds the die mount region; a plurality of metal padsdisposed on the top surface of the core layer and defined by a firstsolder mask layer, wherein the metal pads are plated with at least onemetal; a plurality of flat solder pads disposed on the bottom surface ofthe core layer and defined by a second solder mask layer, the pluralityof solder pads arranged to be within a perimeter of the bottom surfaceof the core layer, wherein the solder pads are plated with at least onemetal; one or more electrical vias located inside the core layer,wherein the vias electrically couple one or more of the plurality ofmetal pads on the top surface of the core layer to one or more of theplurality of solder pads on the bottom surface of the core layer; and atleast one passive electrical element disposed within the core layer andelectrically coupled between one of the plurality of metal pads and oneof the plurality of solder pads, wherein the at least one passiveelectrical element includes a dielectric or resistive material that isdifferent from the printed circuit board material in the core layer;providing a plurality of second housing elements each having arectangular shape, each second housing element formed from a singlepiece of solid material, and having a substantially flat top region anda continuous wall region, the continuous wall region supporting the topregion and adjoining the top region at a substantially perpendicularangle, the continuous wall region having a predetermined height, anexterior surface, an interior surface, and an attachment surface, and anacoustic port located in the top region of the second housing elementand passing completely through the second housing element, wherein theacoustic port is disposed in a position offset from a centerpoint of thesecond housing element; coupling one of the plurality of MEMS microphonedie to one or more of the first housing elements in the unsingulatedpanel of first housing elements, wherein each MEMS microphone die isdisposed in the die mount region of the core layer of its respectivefirst housing element, and electrically coupled to one or more of themetal pads on the top surface of the core layer of its respective firsthousing element; assembling a protective housing for each MEMSmicrophone die mounted on a first housing element in the unsingulatedpanel of first housing elements by coupling one of the second housingelements to each first housing element in the unsingulated panel offirst housing elements having a MEMS microphone die mounted thereon,wherein the attachment surface of the wall region of the second housingelement is aligned with and physically coupled to the attachment regionof the top surface of the core layer of the first housing element,thereby forming a protective enclosure for the MEMS microphone die, andwherein the interior of the protective enclosure is an acoustic chamberhaving a volume defined by the predetermined height of wall region ofthe second housing element, and the width and length of the top regionof the second housing element; and singulating the panel of firsthousing elements into discrete surface mount MEMS microphones.
 37. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 36, wherein the enclosure of each surface mount MEMSmicrophone protects its respective MEMS microphone die from at least oneof light, electromagnetic interference, and physical damage.
 38. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 36, wherein, for one or more of the first secondhousing elements in the unsingulated panel of first housing elements,the top region of the second housing element further includes anacoustic material that substantially blocks contaminants from passingthrough the acoustic port.
 39. A method for manufacturing a plurality ofsurface mount MEMS microphones according to claim 36, wherein, for eachfirst housing element in the unsingulated panel of first housingelements, the core layer of the first housing element further comprisesan internal cavity with an aperture in the top surface of the corelayer, and the MEMS microphone die is positioned over the aperture inthe top surface of the core layer.
 40. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 36,wherein, for each first housing element in the unsingulated panel offirst housing elements, the at least one passive electrical element isconfigured to filter one or more of an input signal, an output signal,or input power.